SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f38b9ffd100f0bb039094947a3408c8d337549aa9d20b63806d59cb971436ced' 
  AND token = 'xxilhbjIFtDLC5fbFGWNjXW8jHLwV4pkkDe2jWfUBrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}